Electron discharge device



Sept. 21, 19 3- L. s. NERGAARD v 2,329,777

ELECTRON DISCHARGE DEVICE Filed Oct. 50, 1941 v I-PI-i-M'In-I INVENTORZeon Jffierymzi W W W ATTORNEY Patented Sept. 21, 1943 7 Leon S. Nergaard', V Yerona, N Ji, assignor toiiadio V I Corporation'of America,a corporation of Dela ware Application Gctobcr so; 1941-, satel ite-[417, 121

V t claims; (01. zit-2&5

' My invention relates to'electron discharge de vices moreparticularlytosuch devices useful atultr-ahigh frequencies.

It is desirableto have-an out-putsystemhaving lowimpedance suitable-foroperation with broadband circuits in the-ultra high frequency field thatthe power dissipating-'ability'of the output:

electrodes imposes nolimitation on the power output. i

It is, therefore,-an object of-my invention to I provide an improvedelectron discharge device suitable ion use athighfrequencies and capableof use with outputsystems having a low output impedance and suitable foroperation with broad band circuits. 4 V It is another-object of-myinvention to provide an electron discharge device suitable for use athigh frequenciesandwhich avoids the use ofhigh frequency leads extendingthrough the tube en- Velope, thus reducing high frequency losses Anotherobject of my invention is to separate the current collector; and outputelectrodes so that the power dissipating ability, of theelectrodesimposes no limitation on the power output. These; and otherobjects will appear hereinafter; The novel features which I believe tobe characteristic of my invention are set forth Withparticularity in theappended claims, but th invention itself'will best be understoodbyireferenceto the following description taken in connection with theaccompanying drawiiig'in which Figure lis aschematic longitudinalsection of an electron discharge device and associated circuit made"according to my invention and'Figure 2 is a'sec-" tion taken alongtheline 2-'2 of Figure 1. V V l Briefly in an electrondischargedevice'madeaccording to my invention, an elongated envelope" contains'at one end acathode and modulating electrode for projecting a beam of electronsaxially of the envelope and a collector electrode is mounted in theother end of the envelope. Adjacent the modulatin grid isa screen andac-' celeratingelectrode and adjacent-the collector isa further screenand accelerating electrode; Positioned between the collector and'modulating electrode and outside of the envelope are-anode segments'having gaps lying-parallel to the longie tioned on opposite sides or te" and line beiiig shieldd wittudinal axis of the? envelope and the"electron stream; Theariode segments are c'ciineted't a paralleltransmission ime, t- -'anode;s e'g niits shielding com partrnentythelifie being turned by p i ope'rl tuning means and energy being extractedby means ofa' loop coupled to the transmissionline; Magnetic means areprovided which cooperate with the other electrodes; to'dtl'mihe thapatlfof the electrons in; the tube'l" Positioned centrally of the anodesegments is" an e1 trodjfor causing eletrons-= pas-sing thiougii tli'eni/elopeadjacent the node Segments"to descrilde-paths close to theenvelope Wall and-the gaps betvvee'z'i the anode segments: v 1

Referring to the drawing; thelongated ez'i-' velope in has positioned atorie ndi th inui: rectly heated cathode Ii'proifidedWith heaterl'l andgrid I Z for" Ifiodijlatilig the electron Strearri whenena, 1 I Icathode and grid: Mounted; atthe other end of the envelope is amnesia-cThe output Iectroaesc'omprisc theanod segmen s IS -11 peso electron;stream between the cathode andcollector and on the outside oftlieei-ivelfif Adjacri'tt hegrid; is a cylindri cs1 eie-cu-cse I 4operatedat a} sufliciently high voltage to preventform one]? a; virtualcathode arid consequent reflection of electrons within the cylinder. Thecylinder-is longeiiough to prevent-coupling-betweri ma ma 'iZ and theoutput electrodes it and Ii.- Adjacent the col: lector is anelectrodefli'which serves-as a sc een and sup iessor ier theeieet-rouele wl'iichcollects V.

the electrons; The collotoi is operated at a volt ge ust to collect anthe electrons;

henc the cciieetor cart-be operated at a lower pote'ntialthah the outputelectrodes;

A roe mete-node H3 exteirds through"thecol lector l3 and suppressor lclairiallfyof-ithe anode segments lfi andil 1 -ele"ot1"o'de-is'- ope-ratedat approximately cathode potential and" operation of the tube reducesthe axial or" lon'gi tudinal velocity of; the electrons and: provides aradial electric field sothat thezelectronsperform alarge number: ofspiral orbits in the electric fieldofthe output-electrodes;

The magnetic iield. is electromagnet s- 2-6 and Z1 and the-field is ad:instead t9 sue ;,e,veli hat m for each orbit of the electrons passingthrough the output electrodes is equal to a period oft'he RsfF. gridvoltage. The poteI-itial of the output electrodes is so adjustedthat-the g rblts' bring-the electrons almost out tothe walloi theenvelope VF; potential-is-" applied betwe'enth' provided by rneansof theI of the tube. The electromagnets also serve to keep the beam focused inpassing through the shield M.

The input circuit may be provided by transmission line H! shorted by thetuning bar 29, the input voltage being coupled into the transmissionline by means of the coupling loop 2|. The anode segments l6--ll areconnected to the output transmission line comprising a pair ofconductors 22 extending in a plane normal to the longitudinal axis ofthe tube envelope and shorted by means of the tuning member or disk 23,slidable on the conductors 22. The output circuit and output electrodesare enclosed within the shielding member 24 which shields the outputfrom the input circuit and prevents undesired radiation, The shortingdisc 23 serves to close the shielding compartment. The shieldingcompartment is provided with extensions 2G and 24", which enclose thecathode, grid and accelerator and the suppressor and collector positioned in opposite ends of the tube envelope. The output transmissionline circuit may be coupledto output coupling loop 25 extending throughthe shorting member or disc into the shielded space.

Suitable sources of voltage 28 provided for the cathode heater, 29forproviding a proper bias on the grid, and 3!! for supplying variousvoltages on the other electrodes are also provided. Suitable connectionsare made for applying a higher voltage to the output electrode segments[6 and I! and the shielding casing 24, and lower voltages to thesuppressor l and collector it. The rod [8 is connected to the cathode soas to have cathode potential applied thereto during operation of thedevice.

Briefly the operation of the device is as follows: an R. F. signal isapplied tothe transmission line l9, which causes an R. F. voltage toappear on the grid l2, which modulates the electron stream from thecathode ll. This modulated stream traverses the shielding electrode I4and enters the space of the output electrode segments 16-41. In thisspace the electrons are slowed down by red i8 and directed outwardly bythe radial electrostatic field between rod 18 and the segments. Theaxial magnetic field causes the electrons to perform spiral orbits, asin a magnetron, and give up energy to the out; put electrodes each timethey cross the gaps or the gap field between the output electrodesegments. The effective current from which the output electrodes obtainpower is thus the, product of the beam current and the number, ofspirals. Since this efiectivecurrent is large the tube is capable oidriving a low impedance load such as encountered in wide bandtransmission. After giving up their energy, electrons are collected bythe collector l3.

While I have indicated the preferred embodiments of my invention ofwhich I am now aware and have also indicated only one specificapplication for which my inventionmay be. employed, it will be apparentthat my invention is by no means limited to the exact form illustratedor the use indicated, but that many variations may be made in theparticular structure used and the purpose for which it is employedwithout departing from the scope of my invention as set forth in theappended claims.

What I claim as new is:

1. An electron discharge device having means for generating a modulatedstream of electrons and an electrode for receiving the electrons in saidstream, output electrode means comprising a plurality of segmentssurrounding the path of the stream and separated by gaps extending alongthe longitudinal axis of said stream, means for causing electrons ofsaid stream to follow spiral orbital paths within the output electrodemeans a plurality of times past the gaps between said plurality ofsegments and then toward said collector, said last means comprisingelectromagnetic means for producing a magnetic field parallel to thelongitudinal axis of said device and a rod positioned within and coaxialof said electrode segments and adapted to be maintained at substantiallycathode potential during operation of said electron discharge device,and an output means comprising a conductor connected to one of saidsegments and another conductor connected to another of said segments,and means electrically joining the conductors remote from said segments.

2. An electron-discharge device having means for generating a modulatedbeam of electrons and a collector for receiving the electrons in saidbeam, output electrode means comprising a plurality of electrodesegments surrounding the path of the beam and separated by gapsextending along the longitudinal axis of said beam, means for causingelectrons of said beam, to follow spiral orbital paths within the outputelectrode means past the gaps between said plurality of segments andthen toward said collector, and an output means comprising a conductorconnected to one of said segments and another conductor, connected toanother of said segments, and a shielding system surrounding saidplurality of segments and said output means and meanselec tricallyjoining the conductors remote from said segments and positioned Withinsaid shield.

3. An electron discharge device having'means for generating amodulatedbeam of electrons and a collector for receiving the electronsin said beam, output electrode means comprising a plurality of electrodesegments surrounding the path of the beam and separated by gapsextending along thelongitudinal axis of said beam, means for causingelectrons of said beam to follow spiral orbital paths within the outputelectrode means a plurality of times past the gaps between saidplurality of segments and then toward said collector, and an outputmeans comprising a conductor connected to oneof said segments andanother conductor connected to another of said segments, and a shieldingsystem surrounding said plurality of segments and said output means, andconducting means slidable within said shielding system and electricallyshorting said conductors and closing the shielding system around saidoutput means.

l. An electron discharge device having an elongated envelope andcontaining means for directing a modulated beam of electronslongitudinally of said envelope, and a collector for col1ecting saidelectrons, output electrode means comprising a plurality of electrodesegments surrounding and closely adjacent the outside of said, envelope,said segments being separated by gaps,

extending along the longitudinal axis of said beam and means for causingelectrons from the cathode to follow, orbital paths within the spacesurrounded by said electrode segments.

5. An electron discharge device having an-elongated envelope andcontainingmeans for directing a modulated beam of electronslongitudinally of said envelope,

and a collector for collecting for causing, electrons from; the cathodeto follow orbitalpathswithin. the space surrounded by. said electrodesegments, said lastmeans comprising electromagnetic means forproducingamagnetic field. parallel to the longitudinal axis of saidenvelope, and a rod positioned axially, ofrsaid electrode segmentsandadaptedrto be'maintained at substantially cathode potential during.operat-ion of said eleotron discharge device.

6; An: electron discharge device having an elongated envelope and:containing means for directing a modulated. beam of. electronsxlomgitudinally oisaid envelope, andca collector for collecting saidielectrons, output electrode means comprisinga. plurality. of electrodesegments surrounding and closely adjacent the outside of said envelope,said segments being separated by gaps and means for causing electronsfrom the oathode to follow orbital paths Within the space surrounded bysaid electrode segments, said last means comprising electromagneticmeans for producing a magnetic field parallel to the longitudinal axisof said envelope, and a rod positioned axially of said electrodesegments and adapted to be maintained at substantially cathode potentialduring operation of said electron discharge device, and conductingmembers connected to different ones of said electrode segments, andmeans electrically connecting said conducting members remote from saidelectrode segments to provide an output transmission line.

7. An electron discharge device having an elongated envelope andcontaining means for directing a modulated beam of electronslongitudinally of said envelope, and a collector for collecting saidelectrons, output electrode means comprising a plurality of electrodesegments surrounding and closely adjacent the outside of said envelope,said segments being separated by gaps and means for causing electronsfrom the oathode to follow orbital paths Within the space surrounded bysaid electrode segments, said last means comprising electromagneticmeans for producing a magnetic field parallel to the longitudinal axisof said envelope, and a rod positioned axially of said electrodesegments and adapted to be maintained at substantially cathode potentialduring operation of said electron discharge device, and conductingmembers connected to difierent ones of said electrode segments, andmeans electrically connecting said conducting members remote from saidelectrode segments to provide an output transmission line, and shieldingmeans surrounding said electrode segments and said conducting membersconnected thereto for preventing radiation from said transmission lineand coupling means associated with said transmission line.

8. An electron discharge device having an elongated envelope and havingat one end a cathode and a grid for supplying a modulated beam ofelectrons longitudinally of said envelope, and a collector at the otherend of said envelope for collecting said electrons, output electrodemeans comprising a plurality of electrode segments surrounding andclosely adjacent the outside of said envelope, said segments beingseparated by gaps, and a shielding. electrode positioned adjacent thegrid for shielding said cathode and grid from said electrode segments,and a second shielding electrode positioned between the, collectors and.said-electrode segments, and means foncausing e1e0trons:from: thecathodeto! follow orbital; paths, within the space sure rounded; by saidelectrode; segments, said last meansv comprising; electromagnetic meansfor producing a magnetic field parallel to, the longi,- tudinal, axis:ofsaidgenyelope, and. a vrod posie tioned, axially of; said; electrodesegments, and adaptedgtobe maintained, atsubstantially cathode potentiaLduring; operation of: said electron, dis,-

charge, device, and: an output means connected to. saidaelectrodesegments, and shielding; means surrounding saict electrode, segmentsand: out:

put means for, preventing: undesired radiation from. saidoutput means. 7

9;; An, electron discharge device having. an elongated: envelopecontaining a, cathode andcontroligridratone-iend of said enveloperorprovide ing astreainpi electrons longitudinally of said envelope, anda collector at the other end of said envelope, a tubular electrodepositioned adjacent the control grid, and a second tubular electrodepositioned adjacent the collector, an output electrode systemsurrounding said envelope between said tubular electrodes and includinga plurality of anode segments separated by gaps extending along thelongitudinal axis of said envelope, and a rod-like electrode extendingaxially of the envelope within the space surrounded by said anodesegments and adapted to be maintained at cathode potential duringoperation of said electron discharge device, and means for providing amagnetic field parallel to and surrounding the rod-like electrode and anoutput means connected to said electrode segments.

10. An electron discharge device having an elongated envelope containingmeans at one end of said envelope for providing a stream of 6160-, tronslongitudinally of said envelope, a control grid adjacent said means anda collector at the other end of said envelope, a tubularelectrodepositioned adjacent the control grid, and a second tubularelectrode positioned adjacent the collector, an output electrode systemsurrounding said envelope between said tubular electrodes and includinga plurality of anode segments separated by gaps extending along thelongitudinal axis of said envelope, and a rod-like electrode extendingaxially of the envelope within the space surrounded by said anodesegments and adapted to be maintained at cathode potential duringoperation of said electron discharge device, and electromagnetic meanssurrounding said envelope for producing a magnetic field longitudinallyof said envelope.

11. An electron discharge device having an elongated envelope containingmeans at one end of said-envelope for supplying a stream of electronslongitudinally of said envelope, a control grid adjacent said means anda collector at the other end of said envelope, a first tubularelecelectrode extending axially of the envelope with-' in the spacesurrounded by said, anode segments and adapted to be maintained atcathode potential during operation of said electron discharge device,and an output means connected I to said electrode segments, andelectromagnetic means for producing a magnetic field longitudinally ofsaid envelope, and a shielding structure surroundingsaid anode segmentsand said output means for preventing undesired radiation therefrom, andhaving extensions surrounding the envelope around the electron supplyingmeans and first tubular electrode and around said collector and secondtubular electrode.

12. An electron discharge device having an elongated envelope containingat one end a cathode and grid for supplying a modulated beam ofelectrons longitudinally of said envelope, and a collector at the otherend of the envelope for collecting the electrons, output electrode meanscomprising aplurality of electrode segments surrounding the path of theelectron stream between said grid and collector, and a shieldingelectrode positioned adjacent the grid for shielding said cathode andgrid from said electrode segments, and a second shielding electrodepositioned between the collector and said electrode segments, and meansfor causing electrons from the cathode to follow orbital paths withinthe space surrounded by said electrode segments, said last meanscomprising electromagnetic means for producing a magnetic field parallelto the longitudinal axis of the envelope and a rod positioned axially ofthe longitudinal axis and adapted to be maintained at substantiallycathode potential during operation of said electron discharge device,and an output means connected to said electrode segments and shieldingmeans surrounding said electrode segments and output means forpreventing undesired radiation from said output circuit and extensionson said shielding means surrounding said cathode and grid and firstshielding electrode and surrounding said second shielding electrode andsaid collector.

LEON S. NERGAARD.

